Method of making beryllium and light alloys thereof



NOV. 13, 1934. I BURGESS K 1,980,378

METHOD 0F MAKING BERYLLIUM AND LIGHT ALLYS THEREOF Original Filed Jan.16, 1952 'lll/lill. Iliff/2.7111111111; 'Il

. NVENTOR Patented Nov. 13, 1934 UNITED STATES METHOD GF MAKINGBERYLLIUM AND LIGHT ALLOYS THEREOF Louis Burgess, New York, N. Y.

Original application January 16, 1932, Serial No.

587,126, now Patent No. 1,937,509, dated December 5, 1933.

Divided and this application November 10, 1933, Serial No. 697,416

9 Claims.

This application is a division of application Serial No. 587,126, filedJanuary 16, 1932, Patent No. 1,937,509, Dec. 5, 1933.

The invention will be fully understood from the following descriptionread in conjunction with the drawing, in which,

Fig. 1 is a vertical section through apparatus in which my invention maybe carried into effect.

Fig. 2 is a vertical section of apparatus in which a further embodimentof my invention may be carried into effect.

Fig. 3 is a cross-section through va further form of apparatus in whichanother embodiment of the invention may be carried out.

Referring specifically to Fig. 1, the apparatus `comprises the casing orshell 1 which may be of iron or steel and which contains the lining orlayer 2 which operates as electrical and thermal insulation between thefluid contents of the apparatus and the shell. vThe lining 2 may eitherbe built up of preformed blocks of suitable refractory material, or maybe formed in situ by filling the shell 1 with fluid electrolyte andpermitting the same to solidify in part adjacent the shell 1 therebyforming the lining 2. 3 designates a bridge wall which may also beformed of suitable refractory material, but is preferably formed in situthrough freezing electrolyte about the pipes 4 which are connected inseries so that a suitable cooling fluid may be circulated through thesame. The layer 5 may, generally speaking, be composed of an alloy ofberyllium with heavier metals which are less electropositive thanberyllium. A number of binary and ternary alloys of this sort may beformed which will operate in the'process. 'I'he alloying metals shouldbe substantially heavier than beryllium, less electropositive thanberyllium in relationship to the electrolyte employed, and the alloyformed should be freely fluid at the temperature of electrolysis. Thealloy must exist as a single homogeneous liquid phase. While silver maybe employed, I prefer to form the layer 5 of an alloy consistingpredominantly of beryllium and copper, or of beryllium and coppercontaining 45 a few percent of silicon, which latter agent will operatewithin certain ranges of concentration to depress the freezing point andimpart greater fluidity. Alternatively, or in addition to the silicon,there may be added a few percent of other metals less electropositivethan beryllium which have a low melting point and are'normally liquid atthe temperature of electrolysis. In any event, the alloy so formedshould have a specific gravity in excess of 3 at the temperature ofvelectrolysis. The layer 6 indicates generally a suitable electrolytecontaining an electrolyzable beryllium compound, and in whichelectrolyte the beryllium compound has a lower voltage of dissociationthan the other constituents present, unless of course the process isoperated to simultaneously produce an alloy of other elements thanberyllium. Preferably, however, the beryllium compound present in theelectrolyte is the most easily dissociable compound upon electrolysis.Within the limits of temperature at which the alloy consisting ofberyllium andcopper is fluid, the electrolyte must consist essentiallyof fluorides. It may consist predominantly of another fluoride orfluorides of higher dissociation potential than beryllium fluoride,containing in solution a few percent of beryllium fluoride and/orberyllium oxide. Preferably, however, the electrolyte 6 contains asubstantial proportion of beryllium fluoride, and to impart the maximumfluidity and conductivity at least one fluoride with an element moreelectropositive than beryllium and which therefore forms a uoride ofhigher dissociation potential should be present. The iluorides of thealkali metal and alkaline earth metals conform to this description. Inthis case, a' few percent of beryllium oxide may be present dissolved inthe fluoride electrolyte. 10 indicates an anode which may be of anysuitable type, but preferably consists of a rod of carbon or graphitizedcarbon carried by the holder 11. It Ywill of course be understood that anumber of such rods areemployed in parallel sufficient to carry therequisite amperage into the apparatus. In carrying out the operation,current is applied to the anode 10 whereby the electrolyte 6 iselectrolyzed in series with the alloy layer 5 as cathode, therebydissociating the beryllium compound in solution in the electrolyte 6 andliberating beryllium at the surface 12 of the alloy 5. The alloy willundergo considerable flow during electrolysis due principally to theelectrical field to which it is subjected, and the beryllium liberatedat' the surface 12 will therefore be incorporated with the main body ofthe alloy. In order to produce the elemental beryllium, either per se orin the form of a light alloy of beryllium, the alloy layer 5 iselectrolyzed as anode through a suitable electrolyte in series with asuitable cathode. This may, generally speaking, be done eithersimultaneously with or in succession to the steps hereinbeforedescribed. In the apparatus illustrated in Figs. 1 and 2, the secondstage electrolysis with the copper beryllium alloy as anode is carriedsimultaneously with the, first stage electrolysis hereinbeforederlblifl. 1 1). this case, the fluid electrolyte 13 floats upon a partof the alloy layer 5. The cathode 14 may be of any suitable type andpreferably consists of a rod of carbon or graphitized carbon carried bya suitable holder 15. It will ofcourse be understood that while one rodis diagrammatically shown for purposes of illustration, a number of suchrods will be employed in parallel, depending upon the total amperage tobe carried through the electrolyte. When making pure beryllium unalloyedwith other metals, th'e material will plate out in solid phase as a body16 of metal adhering to the lower end of the cathode 14. Owing to thefact that the boiling or sublimation temperature of beryllium is veryclose 'to the melting point, the beryllium isv plated out on to thecathode 14 in solid form. 'I'he temperature of electrolysis may rangefrom a temperature in the electrolyte approaching the melting point ofberyllium down to the lowest temperature at which the alloy layer 5 andthe electrolyte will be freely fluid. When operating with an alloy layer5 consisting almost entirely of copper and beryllium, temperatures offrom 950to 1250 are preferred. A temperature of from 1100to 1200 ispreferred. In this case the alloy layer 5 preferably contains from 4 to12% by Weight of beryllium. The addition of other metals to the alloylayer 5, which depress the freezing point, will materially extend therange of temperatures within which the operation may be eilcientlycarried out,`

and will also render it possible to operate with higher percentages ofberyllium. Where the alloy layer 5 consists entirely of copper andberyllium, the melting point starts to rise sharply as the berylliumcontent is increased above 10%. The applied voltage will be sufficientto carry the necessary amperage through the furnace, and the two factorsof amperage and voltage will be so correlated as to maintain the desiredpredetermined temperature. 'Ihe electrolyte layer 6 and 13 may vary froma few up to several inches in thickness. The amperage will be, generallyspeaking, in the neighborhood of 1000 amperes per square foot. It isalways possible by increasing th`e thickness of the electrolyte toincrease the specific resistance of the cell and correspondinglyincrease the temperature of operation. Diminishing the thickness of theelectrolyte layers will have the converse effect.

In the modified apparatus shown in Fig. 2, corresponding parts have beenidentified by corresponding numerals. The apparatus shown in Fig. 2 is,however, designed to eliminate the necessity for removing solidberyllium from the extremity of the cathode 14 and tp permit thematerial to be handled in liquid phase. In this case the rod 1.4contacts with a layer 20 of light metal or alloy floating upon theelectrolyte 13. This may for example be a layer of beryllium aluminumalloy, or may alternatively at the start of the operation be a layer ofpure aluminum. In either event, the electrolyte must be so compounded asto float the layer 20 which is in this case the true cathode throughoutthe entire range of concentrations. In general, the layer 20 will becomelighter during electrolysis owing to increase in its beryllium content,and the electrolyte should be compounded to support the layer 20 in itscondition of maximum density. In this case, particular attention must bepaid to the composition of the electrolyte, and iluorides of the alkalimetal and/or alkaline earth metals must be present in sufficient amountsto make the electrolyte more dense than the layer 20 throughout theentire operation. This may be effected by the use of barium fluoride andPercent Beryllium fluoride-; 20-25 Barium fluoride 35-40 Potassiumfluoride 35-40 With the apparatus shown in Fig. 2, the operation iscontinued until the layer 20 has attained the desired concentration ofberyllium. The concentration of beryllium in the layer 20 must not bepermitted to reach such a point as to cause soldiiication or thickeningof the same. The danger point may, however, be readily determined bycomparing the temperature of electrolysis with tables showing themelting points of beryllium aluminum alloys. When the predeterminedconcentration of beryllium has been reached in the layer 20, it may betapped from the cell into any suitable receiving vessel through thetapping duct 21 which is normally closed by means of the plug 22. Whenthis has been done, the layer 20 is replenished either with purealuminum, or an alloy of beryllium and aluminum containing less than thedesired beryllium content and operations resumed.

During the operation, fluorine generated in the first stage ofelectrolysis at the lower extremity of the anode 10 will pass out of theapparatus without contact with the beryllium or aluminumA alloyundergoing formation. This eliminates complications due to the presenceof fluorine and beryllium in the same space as it occurs in the ordinaryand prior art method of generating beryllium. The elimination of thefluorine at the lower end of the anode 10, moreover, renders it possibleto Yfloat the cathode layer 20 on the electrolyte -13. tion may becarried out without replenishment of the beryllium compound in theelectrolyte 6, it is preferably carried out with the intermittent orcontinuous replenishment of the beryllium compound in the same so as tomaintain a substantial uniform composition of the electrolyte 6throughout the operation. The electrolyte 13 does not normally undergosubstantial change, inasmuch as beryllium passes into the same from thealloy 5 in amounts equal to that liberated at the cathode 14. Thecomposition of the alloy layer 5 will not undergo substantial change inoperation as the amount of beryllium abstracted from this layer issubstantially balanced by that introduced.

'I'he operation may be effectively carried out in the relatively simpleapparatus shown in Fig. 3.4 This comprises the shell 30 which carriesthe carbon lining 31 adjacent the interior lower portion of the shell.This may consist of a carbon lining tamped into position and suitablybonded, or may alternatively consist of preformed carbon blocks laid andcemented in position. 'I'he block type has been illustrated in thefigure. Electrical'contact with the carbon lining or pit may be made inany suitable manner. In the form illustrated, the block 32 adjacent thefloor of the shell 30 is formed with a machined cylindrical butt 33which fits snugly into the annular water cooled sleeve 34. This issealed tc the shell 30 and carries the end closure 35 to which thebus-bar 36 is connected. The upper part of the shell carries a thermallyand electrically insulating lining 40, preferably formed in situ byfreezing electrolyte on the walls of the shell.

While the opera-v 'I'he electrode 41 which may consist of carbon d orgraphitized carbon is carried by the holder 42 and several suchelectrodes are employed in parallel to carry the requisite amperage. Thepit 31 carries the alloy 5 hereinbefore described, and the electrolyte43 is provided floating upon the surface of the fluid alloy 5. Inoperating this apparatus, electrolysis is carried out for a period withthe electrode 41 as anode and the alloy 5 as cathode. During thisperiod, the concentration of beryllium in the layer 5 is continuouslyincreasing. Before the concentration of beryllium in the layer 5 reachessuch a point as to cause undue loss of fluidity or freezing, theoperation is reversed, making the layer 5 anode and the electrode 41cathode, so that the beryllium is plated out on the lower end of theelectrode 41. As the layer 5 becomes impoverished in beryllium, theoperation is discontinued and the beryllium removed from the lower endof the electrode 41. The electrolyte does not change in compositionduring the second stage of operation and is preferably held constant bysuitable replenishments during the first stage.

In the preferred method of operating this apparatus, the electrolyte iscompounded as hereinbefore described to support a cathode layer ofaluminum or of beryllium aluminum alloy consisting principally ofaluminum. In this case, electrolysis is started with the electrode 4l asanode and the alloy layer 5 as cathode and carried out preferably 'with'suitable replcnishments of the dissociated beryllium compound until thelayer 5 has become enriched in beryllium content. The operation is thentemporarily discontinued. The electrode 41 is raised slightly and alayer of molten aluminum or aluminum beryllium alloy is gentlyintroduced, so that it floats on the surface of the electrolyte 43. Theelectrode 41 is then adjusted to contact with the fluid metalintroduced, which latter then becomes the true cathode. Electrolysis isthen continued with the alloy layer 5 as anode and the introduced lightmetal as cathode until the a1- loy 5 has become impoverished inberyllium, whereupon the light metal which has now becomecorrespondingly enriched in beryllium is tapped into a suitablereceiving vesselv through the duct 44 which is normally closed by theplug 45.

The foregoing description is for purposes of illustration, and it istherefore my intention that the invention be limited only by theappended claims or their equivalents in which I have endeavored to claimbroadly all inherent novelty.

I claim:

1. Process of making a beryllium aluminum alloy, which comprisesmaintaining a fluid alloy consisting predominantly of'beryllium andcopper, maintaining floating on at least a nart of the said fluid alloya fluid electrolyte containing a metallic fluoride or fluorides ofhigher dissociation potential than beryllium fluoride and containing acompound selected from the group consisting of beryllium fluoride andberyllium o-xide, electrolyzing said electrolyte in series with saidalloy as cathode and with a suitable anode, thereby dissociating saidberyllium compound, liberating beryllium at said cathode and adding tothe beryllium in the said fluid alloy, maintaining floating on at leasta part of the said fluid alloy an electrolyte containing a metallicfluoride or fluorides of higher dissociation potential than berylliumfluoride and containing a compound selected from the group consisting ofberyllium fluoride and beryllium oxide, maintaining floating on saidlast mentioned electrolyte a fluid layer of beryllium-aluminum alloy,and electrolyzing said last mentioned electrolyte in series with saidberyllium copper alloy as anode and with said beryllium aluminum layeras cathode, thereby adding to the beryllium contained in said berylliumaluminum alloy.

2. Process of making a beryllium aluminum alloy, which comprisesmaintaining a fluid alloy consisting predominantly of beryllium andcopper, maintaining oating on at least a part of the said fluid alloy auid electrolyte containing a metallic fluoride or fluorides of higherdissociation potential than beryllium fluoride and containing a compoundselected from the group consisting of beryllium fluoride and berylliumoxide, electrolyzing said electrolyte in series with said alloy ascathode and with a suitable anode, thereby dissociating said berylliumcompound, liberating beryllium at said cathode and adding to theberyllium in the said fluid alloy, maintaining floating on at least apart of the said fluid alloy an electrolyte containing a metallicfluoride or fluorides of higher dissociation potential than berylliumfluoride and containing a compound selected from the group consisting ofberyllium fluoride and beryllium oxide, maintaining floating on saidlast mentioned electrolyte a fluid layer of beryllium-aluminum alloy,and electrolyzing said. last mentioned electrolyte in series with saidberyllium copper alloy as anode and with said beryllium aluminum layeras cathode, thereby adding to the beryllium contained in said berylliumaluminum alloy.

3. Process of making a, beryllium aluminum alloy, which comprisesmaintaining a fluid alloy consisting predominantly of beryllium and ametal or metals relatively more dense than beryllium and lesselectropositive than beryllium in relation to fluorine, maintainingfloating on at least a part of said alloy a fluid .electrolytecontaining a metallic fluoride or fluorides selected from the alkalimetal and alkaline earth metal uorides and containing a compoundselected from the group consisting of beryllium fluoride and berylliumoxide, electrolyzing said electrolyte in series with said alloy ascathode and with a suitable anode, thereby dissociating said berylliumcompound, liberating beryllium at the said cathode and adding to theberyllium in said fluid alloy, maintaining floating on at least a partof the said fluid alloy a fluid electrolyte containing a metallicfluoride or fluorides selected from the alkali metal and alkaline earthmetal fluorides and containing a compound selected from the groupconsisting of beryllium fluoride and beryllium oxide, maintainingfloating on said last mentioned electrolyte a fluid beryllium-aluminumalloy, and electrolyzing said last mentioned electrolyte in series withsaid first mentioned alloy as anode and in series with said berylliumaluminum alloy as cathode, thereby adding to the beryllium in saidberyllium aluminum alloy.

4. Process of making a beryllium aluminum alloy, which comprisesmaintaining a fluid alloy of beryllium and a metal or metals relativelymore dense than beryllium and less electropositive than beryllium inrelation to fluorine, maintaining floating on a part of the said fluidalloy a fluid layer of electrolyte containing a metallic fluoride orfluorides of higher dissociation potential than beryllium fluoride andcontaining a compound selected from the group consisting of berylliumfluoride and beryllium oxide, electrolyzing said electrolyte in serieswith said alloy as cathode and with a suitable anode, therebydissociating said beryllium compound, liberating beryllium at the saidcathode and adding to the beryllium in the said fluid alloy, maintainingfloating on a part of the said fluid alloy a second fluid electrolytecontaining a metallic fluoride or fluorides of higher dissociationpotential than beryllium fluoride and containing a compound selectedfrom the group consisting of beryllium fluoride and beryllium oxide,maintaining floating on the said second electrolyte a fluid layer ofberyllium-aluminum alloy, electrolyzing said second electrolyte inseries with said first mentioned alloy as anode and with said berylliumaluminum alloy as cathode, thereby adding to the beryllium in the saidberyllium-aluminum alloy. i f

5. Process of making beryllium aluminum alloy, which comprisesmaintaining a fluid alloy consisting predominantly` of beryllium andcopper, maintaining floating on a part of the said fluid alloy a fluidlayer of electrolyte containing a metallic fluoride or fluorides ofhigher dissociation potential than beryllium fluoride and containing acompound selected from the group consisting of beryllium fluoride andberyllium oxide, electrolyzing said electrolyte in series with saidalloy as cathode and with a suitable anode, thereby dissociating saidberyllium compound, liberating beryllium at the said cathode and addingto the beryllium in the said alloy, maintaining floating on a part ofthe said fluid beryllium copper alloy a second fluid electrolytecontaining a metallic fluoride or fluorides of higher dissociationpotential than beryllium fluoride and containing a compound selectedfrom the group consisting of beryllium fluoride and beryllium oxide,maintaining floating on'the said second electrolyte a fluid layer ofberyllium aluminum alloy, electrolyzing said second electrolyte inseries with said beryllium copper alloy as anode and With said berylliumaluminum alloy as cathode, thereby adding to the beryllium in the saidberyllium aluminum alloy.

6. Process of making a beryllium aluminum alloy, which comprisesmaintaining a fluid alloy of beryllium and a metal or metals relativelymore dense than beryllium and less electropositiv'e'than beryllium inrelation to fluorine, maintaining floating on a part of the said fluidalloy a. fluid layer of electrolyte containing a metallic fluoride orfluorides selected from the alkali metal and alkaline earth metalfluorides and containing a compound selected from the group consistingof beryllium fluoride and beryllium oxide, electrolyzing saidelectrolyte in series with said alloy as cathode and with a suitableanode, thereby dis.

sociating the said beryllium compound, liberating beryllium at the saidcathode and adding to the beryllium in said fluid alloy, maintainingfloating on a part of the said fluid alloy an electrolyte containing afluoride or fluorides selected from y the alkali metal and' alkalineearth metal fluorides, maintaining floating on said last mentionedelectrolyte a beryllium aluminum alloy, and electrolyzing said lastmentioned electrolyte in series with said first mentioned alloy as anodeand in series with said beryllium aluminum alloy as cathode', therebyadding to the beryllium in the said beryllium aluminum alloy,

7. Process of making a beryllium aluminum alloy, which comprisesmaintaining a fluid alloy of beryllium and a metal or metals relativelymore'dense than beryllium and less electropositive than beryllium inrelation to fluorine, maintaining floating on the said fluid alloyafluid layer of' thereby adding to the beryllium in said berylliumaluminum alloy. y

8. Process of making a beryllium aluminum alloy, which comprisesmaintaining a fluid alloy consistingI predominantly of beryllium andcopper, maintaining floating on said fluid alloy a fluid electrolytecontaining a metallic fluoride or fluorides of higher dissociationpotential than beryllium fluoride and containing a compound selectedfrom the group consisting of beryllium fluoride' and beryllium oxide,electrolyzing said electrolyte in serieswith said alloy as cathode andwith a suitable anode, thereby dissociating said beryllium compound,liberating beryllium atthe said cathode and adding to the beryllium insaid fluid alloy, thereafter reversing the electrolysis, maintainingfloating on the said electrolyte a fluid layer of beryllium aluminumalloy and electrolyzing the said electrolyte in series with said firstmentioned alloy as anode and with said beryllium aluminum layer ascathode, thereby adding to the beryllium contained in said berylliumaluminum alloy. l

9. Process of making a beryllium aluminum alloy, which comprisesmaintaining a fluid alloy ofberyllium and a metal or metals more densethan beryllium and less electropositive than beryllium in relation tofluorine, maintaining floating on said fluid alloy a fluid electrolytecontaining a metallic fluoride or fluorides selected from the alkalimetal and alkaline earth metal fluorides and containing a compoundselected from the group consisting of beryllium fluoride and berylliumoxide, electrolyzing the said electrolyte in series with said alloy ascathode and with a suitable anode, thereby dissociating said berylliumcompound, liberating beryllium at the said cathode and adding to tht.`beryllium in said fluid alloy, thereafter reversing the electrolysis,maintaining floating on said electrolyte a fluid beryllium aluminumalloy, and electrolyzng said electrolyte in series with saidflr'stmentioned alloy as anode and in series with said berylliumaluminum alloy as cathode, thereby adding to the beryllium in saidberyllium aluminum alloy.

LOUIS BURGESS.

